Analysis of The Possible Numbers of Battery Switching Station (BSS)

Based on what has been discussed in chapter 1 at case description, this thesis project scope is for a company that uses medium duty truck as a delivery vehicle to distribute demand in the Netherlands. As has been mentioned before, battery switching station is still considered as a new concept for charging infrastructure, and it has not been used widely. In Netherlands, there is no battery switching station that can be used as a recharging facility for an electric truck.

The idea for battery switching station is to copy the gasoline station idea, which makes the vehicle only need a short time to get new power or energy. Therefore, battery switching station that only needs three until ten minutes to make vehicle gets a fully charged battery is a good option as charging infrastructure for a commercial vehicle that considers time as an important factor in the operational level. Nevertheless, this advantages of battery switching station can not be achieved if the accessibility of station is poor, such as the electric truck needs to travel far from its original delivery route to access battery switching station. Therefore, battery switching station also needs to copy the easy accessibility of those of gasoline station by making it possible for an electric truck to travel not far from its original route to reach BSS.

Based on this, the numbers of BSS needs to be built high enough and needs to be spread in the Netherlands such that it will be easy for the electric truck to access it. To find out the numbers of

12

the possible battery switching station should be built, the frequency of electric truck needs to visit BSS based on electric vehicle’s maximum range distance and maximum daily distance travelled should be analysed first. Following this, the number of possible BSS is calculated based on the allowable time to reach BSS.

2.1.1. Transportation Operation Assumptions and Frequency to Visit BSS (𝒇𝒇_𝒇𝒇)

Since the working place is in the Netherlands, the working condition and regulation regarding truck and driver in the Netherlands should be investigated first as a base of building assumption and designing the mathematical model. Based on the interviews and correspondences with DHL and KLG of Netherlands, there are several characteristics of a delivery truck and driver’s working condition that are important to be noting:

1. In normal case, most truck will be driven by one driver in one day; therefore the truck will be operated in one shift for one day

2. Most of the distributions have time windows during daylight; this means that majorly trucks will be operated at the same time

3. The driving hours for the driver is based on the UE regulation, which states that daily driving hours should not exceed nine hours, and it can be extended to ten hours only twice a week. Furthermore, after working for working for six days, each driver should have weekly rest. Based on this, the approximation of daily working hours for drivers or daily operated hours of trucks can be calculated:

𝐷𝐷𝐷𝐷𝐷𝐷𝐷𝐷𝐷𝐷 𝑤𝑤𝑤𝑤𝑤𝑤𝑤𝑤𝐷𝐷𝑤𝑤𝑤𝑤 ℎ𝑤𝑤𝑜𝑜𝑤𝑤𝑜𝑜 =𝑡𝑡𝑡𝑡𝑡𝑡𝑡𝑡𝑡𝑡 𝑚𝑚𝑡𝑡𝑚𝑚𝑖𝑖𝑚𝑚𝑚𝑚𝑚𝑚 𝑤𝑤𝑡𝑡𝑤𝑤𝑖𝑖𝑖𝑖𝑤𝑤𝑤𝑤 ℎ𝑡𝑡𝑚𝑚𝑤𝑤𝑜𝑜 𝑖𝑖𝑤𝑤 𝑡𝑡𝑤𝑤𝑒𝑒 𝑤𝑤𝑒𝑒𝑒𝑒𝑖𝑖

𝑤𝑤𝑚𝑚𝑚𝑚𝑛𝑛𝑒𝑒𝑤𝑤 𝑡𝑡𝑜𝑜 𝑑𝑑𝑡𝑡𝑑𝑑𝑜𝑜 𝑖𝑖𝑤𝑤 𝑡𝑡𝑤𝑤𝑒𝑒 𝑤𝑤𝑒𝑒𝑒𝑒𝑖𝑖 (1)

𝐷𝐷𝐷𝐷𝐷𝐷𝐷𝐷𝐷𝐷 𝑤𝑤𝑤𝑤𝑤𝑤𝑤𝑤𝐷𝐷𝑤𝑤𝑤𝑤 ℎ𝑤𝑤𝑜𝑜𝑤𝑤𝑜𝑜 =9 ℎ𝑡𝑡𝑚𝑚𝑤𝑤𝑜𝑜 𝑚𝑚 4 𝑑𝑑𝑡𝑡𝑑𝑑𝑜𝑜+10 ℎ𝑡𝑡𝑚𝑚𝑤𝑤𝑜𝑜 𝑚𝑚 2 𝑑𝑑𝑡𝑡𝑑𝑑𝑜𝑜 6 𝑑𝑑𝑡𝑡𝑑𝑑𝑜𝑜

𝐷𝐷𝐷𝐷𝐷𝐷𝐷𝐷𝐷𝐷 𝑤𝑤𝑤𝑤𝑤𝑤𝑤𝑤𝐷𝐷𝑤𝑤𝑤𝑤 ℎ𝑤𝑤𝑜𝑜𝑤𝑤𝑜𝑜 =56 ℎ𝑡𝑡𝑚𝑚𝑤𝑤𝑜𝑜

6 𝑑𝑑𝑡𝑡𝑑𝑑𝑜𝑜 = 9.33 ℎ𝑤𝑤𝑜𝑜𝑤𝑤𝑜𝑜/𝑑𝑑𝐷𝐷𝐷𝐷

To know the frequency of electric truck needs to visit BSS in one day, the maximum daily distance can be travelled by truck and electric truck’s limited range should be found out. To analyse the maximum daily distance can be travelled by truck, the average speed of truck in Netherlands needs to be known. Based on the Netherlands regulation, the maximum speed truck in are:

-31mph or 50 km/hour in built up area -50 mph or 80km/hour outside built up area - 62 mph or 100km/hour at expressways

For this case, it is assumed that in Netherland, the average speed for delivery truck is same with the maximum speed of truck in the built up area, which is 31mph or 50 km/h. This assumption is made since this speed is in the range of delivery truck’s average speed based on Walkowich (2017). He states that the delivery truck’s speed is around 48-56 km/hours. Therefore, the maximum daily distance travelled by truck is:

𝑀𝑀𝐷𝐷𝑀𝑀𝐷𝐷𝑀𝑀𝑜𝑜𝑀𝑀 𝐷𝐷𝐷𝐷𝐷𝐷𝐷𝐷𝐷𝐷 𝐷𝐷𝐷𝐷𝑜𝑜𝐷𝐷𝐷𝐷𝑤𝑤𝐷𝐷𝐷𝐷 = 𝐷𝐷𝑎𝑎𝐷𝐷𝑤𝑤𝐷𝐷𝑤𝑤𝐷𝐷 𝑜𝑜𝑠𝑠𝐷𝐷𝐷𝐷𝑑𝑑 𝑀𝑀 𝑀𝑀𝐷𝐷𝑀𝑀𝐷𝐷𝑀𝑀𝑜𝑜𝑀𝑀 𝑑𝑑𝐷𝐷𝐷𝐷𝐷𝐷𝐷𝐷 𝑤𝑤𝑤𝑤𝑤𝑤𝑤𝑤𝐷𝐷𝑤𝑤𝑤𝑤 ℎ𝑤𝑤𝑜𝑜𝑤𝑤𝑜𝑜 (2) 𝑀𝑀𝐷𝐷𝑀𝑀𝐷𝐷𝑀𝑀𝑜𝑜𝑀𝑀 𝐷𝐷𝐷𝐷𝐷𝐷𝐷𝐷𝐷𝐷 𝐷𝐷𝐷𝐷𝑜𝑜𝐷𝐷𝐷𝐷𝑤𝑤𝐷𝐷𝐷𝐷 = 9.33 ℎ𝑤𝑤𝑜𝑜𝑤𝑤𝑜𝑜 𝑀𝑀 50 𝑤𝑤𝑀𝑀/ℎ𝑤𝑤𝑜𝑜𝑤𝑤𝑜𝑜

𝑀𝑀𝐷𝐷𝑀𝑀𝐷𝐷𝑀𝑀𝑜𝑜𝑀𝑀 𝐷𝐷𝐷𝐷𝐷𝐷𝐷𝐷𝐷𝐷 𝐷𝐷𝐷𝐷𝑜𝑜𝐷𝐷𝐷𝐷𝑤𝑤𝐷𝐷𝐷𝐷 = 466.5 𝑤𝑤𝑀𝑀

13

Based on the information from DHL and KLG and truck’s speed assumption, it is assumed that a logistics company for this thesis project has the transportation operation activity’s characteristics as:

1. The company operates all of its vehicles to deliver demand in the Netherlands every day for 260 working days in one year

2. The trucks operate for 9.33 hours per day and work at the same hours 3. The trucks are driven with the average speed of 50km/hour

4. Maximum daily distance travelled by each truck is 466.5 km

5. Since there is no information regarding the number daily demand distribution and demand location distribution, it is assumed that the company will have daily normal demand distribution and the demand is uniformly distributed in the Netherlands

These assumptions are used as a foundation to build the model.

To estimate the frequency of electric truck to visit BSS in one day, other information regarding the maximum driving distance of electric truck with a fully charged battery needs to be found. For this case, the maximum distance range for the electric truck is assumed to be 322 km. This assumption is made for the near future electric truck technology. For present technology, the normal medium electric delivery truck can travel around 161 km, such as an e-Navistar truck. The longer limited distance range can be reached by Emoss truck, which is 100-250 km (emoss.biz, 2017). Since there is the development of battery technology to increase the distance range of a fully charged battery truck, this distance range is predicted to increase. The value of maximum range distance for the electric truck is also based on the plan of Tesla to develop an electric truck that can reach 322-483 km (wired.com, 2017).

Based on the assumption of distance range of electric truck, being 322, and the maximum distance travelled of delivery truck in Netherlands, being 466.5 km, it can be concluded that if electric truck goes out from depot with fully charged battery, it still needs to visit battery switching station to get fully charged battery to reach its maximum distance. The frequency to visit BSS each day at year-j (𝑓𝑓_𝑖𝑖) can be calculated as:

𝑓𝑓_𝑖𝑖= �𝑡𝑡𝑎𝑎𝑒𝑒𝑤𝑤𝑡𝑡𝑤𝑤𝑒𝑒 𝑜𝑜𝑠𝑠𝑒𝑒𝑒𝑒𝑑𝑑 𝑚𝑚 𝑚𝑚𝑡𝑡𝑚𝑚𝑖𝑖𝑚𝑚𝑚𝑚𝑚𝑚 𝑑𝑑𝑡𝑡𝑖𝑖𝑡𝑡𝑑𝑑 𝑤𝑤𝑡𝑡𝑤𝑤𝑖𝑖𝑖𝑖𝑤𝑤𝑤𝑤 ℎ𝑡𝑡𝑚𝑚𝑤𝑤𝑜𝑜

𝑅𝑅𝑗𝑗 � (3)

𝑓𝑓_𝑖𝑖= �𝑀𝑀𝑡𝑡𝑚𝑚𝑖𝑖𝑚𝑚𝑚𝑚𝑚𝑚 𝐷𝐷𝑡𝑡𝑖𝑖𝑡𝑡𝑑𝑑 𝐷𝐷𝑖𝑖𝑜𝑜𝑡𝑡𝑡𝑡𝑤𝑤𝐷𝐷𝑒𝑒

𝑅𝑅𝑗𝑗 �

𝑓𝑓𝑖𝑖= �⁵⁰

𝑘𝑘𝑘𝑘

ℎ𝑚𝑚 9.33ℎ𝑡𝑡𝑚𝑚𝑤𝑤𝑜𝑜

322 𝑖𝑖𝑚𝑚 � = ⌊1.4⌋ = 1

With 𝑓𝑓_𝑖𝑖 as the frequency to visit BSS each day at year-j and 𝑅𝑅_𝑖𝑖 as the limited distance range of electric truck at year-j. For this case, as the range distance is assumed to be 322 km from the starting year, the 𝑓𝑓_𝑖𝑖 will be either one or zero when the range distance increase in the future years.

14 2.1.2. Possible Numbers of BSS

Because there are no fixed delivery routes and it is assumed that the routes can always change, there is no location plan for BSS that will be placed exactly on the delivery route. Therefore there is a possibility that electric trucks need to go out from its original delivery route to visit BSS. It is assumed that the driver can go out from its original delivery route to reach BSS during a limited period and go back to the delivery route; therefore there will be additional distance need to travel by truck to recharge its power. However, it is worth noting that this additional distance is still included the maximum distance of e-truck can travel, which is 466.5 km because the time to go round trip to BSS is included in working hours. Based on this, there will be the allowable distance that truck can travel to get the full charged battery and go back to its original delivery route. This allowable distance can be found out from the allowable time to go round trip to BSS that is decided based on the company policy.

𝐷𝐷𝐷𝐷𝑜𝑜𝐷𝐷𝐷𝐷𝑤𝑤𝐷𝐷𝐷𝐷 𝐷𝐷𝑤𝑤 𝑤𝑤𝑤𝑤 𝑤𝑤𝑤𝑤𝑜𝑜𝑤𝑤𝑑𝑑 𝐷𝐷𝑤𝑤𝐷𝐷𝑠𝑠 𝐷𝐷𝑤𝑤 𝐵𝐵𝐵𝐵𝐵𝐵 =𝑡𝑡𝑎𝑎𝑒𝑒𝑤𝑤𝑡𝑡𝑤𝑤𝑒𝑒 𝑜𝑜𝑠𝑠𝑒𝑒𝑒𝑒𝑑𝑑 𝑚𝑚 𝑡𝑡𝑡𝑡𝑡𝑡𝑡𝑡𝑡𝑡 𝑡𝑡𝑡𝑡𝑡𝑡𝑡𝑡𝑤𝑤𝑡𝑡𝑛𝑛𝑡𝑡𝑒𝑒 𝑡𝑡𝑖𝑖𝑚𝑚𝑒𝑒 𝑡𝑡𝑡𝑡 𝑤𝑤𝑡𝑡 𝑤𝑤𝑡𝑡𝑚𝑚𝑤𝑤𝑑𝑑 𝑡𝑡𝑤𝑤𝑖𝑖𝑠𝑠 𝑡𝑡𝑡𝑡 𝐵𝐵𝐵𝐵𝐵𝐵

𝐹𝐹𝑤𝑤𝑒𝑒𝐹𝐹𝑚𝑚𝑒𝑒𝑤𝑤𝐷𝐷𝑑𝑑 𝑡𝑡𝑡𝑡 𝑎𝑎𝑖𝑖𝑜𝑜𝑖𝑖𝑡𝑡 𝐵𝐵𝐵𝐵𝐵𝐵𝑗𝑗 (4) 𝐷𝐷𝐷𝐷𝑜𝑜𝐷𝐷𝐷𝐷𝑤𝑤𝐷𝐷𝐷𝐷 𝐷𝐷𝑤𝑤 𝑤𝑤𝑤𝑤 𝑤𝑤𝑤𝑤𝑜𝑜𝑤𝑤𝑑𝑑 𝐷𝐷𝑤𝑤𝐷𝐷𝑠𝑠 𝐷𝐷𝑤𝑤 𝐵𝐵𝐵𝐵𝐵𝐵 =𝑡𝑡𝑎𝑎𝑒𝑒𝑤𝑤𝑡𝑡𝑤𝑤𝑒𝑒 𝑜𝑜𝑠𝑠𝑒𝑒𝑒𝑒𝑑𝑑 𝑚𝑚 𝑡𝑡𝑡𝑡𝑡𝑡𝑡𝑡𝑡𝑡 𝑡𝑡𝑡𝑡𝑡𝑡𝑡𝑡𝑤𝑤𝑡𝑡𝑛𝑛𝑡𝑡𝑒𝑒 𝑡𝑡𝑖𝑖𝑚𝑚𝑒𝑒 𝑡𝑡𝑡𝑡 𝑤𝑤𝑡𝑡 𝑤𝑤𝑡𝑡𝑚𝑚𝑤𝑤𝑑𝑑 𝑡𝑡𝑤𝑤𝑖𝑖𝑠𝑠 𝑡𝑡𝑡𝑡 𝐵𝐵𝐵𝐵𝐵𝐵

�𝑎𝑎𝑎𝑎𝑎𝑎𝑎𝑎𝑎𝑎𝑎𝑎𝑎𝑎 𝑠𝑠𝑠𝑠𝑎𝑎𝑎𝑎𝑠𝑠 𝑥𝑥 𝑘𝑘𝑎𝑎𝑥𝑥𝑚𝑚𝑘𝑘𝑚𝑚𝑘𝑘 𝑠𝑠𝑎𝑎𝑚𝑚𝑑𝑑𝑑𝑑 𝑤𝑤𝑤𝑤𝑎𝑎𝑘𝑘𝑚𝑚𝑤𝑤𝑎𝑎 ℎ𝑤𝑤𝑚𝑚𝑎𝑎𝑠𝑠

𝑅𝑅𝑗𝑗 �

Since the delivery truck deliver demand for 9.33 hours per day, to make truck does not loose much time to get its fully charged battery, it is assumed that the allowable time to go round trip to BSS and back to truck’s original delivery route is 0.5 hours, which is only 5.2% of total working time. Based on this assumption, and the previous assumption about average speed for truck and limited distance range of electric truck, the allowable distance to go round trip to BSS can be calculated:

𝐷𝐷𝐷𝐷𝑜𝑜𝐷𝐷𝐷𝐷𝑤𝑤𝐷𝐷𝐷𝐷 𝐷𝐷𝑤𝑤 𝑤𝑤𝑤𝑤 𝑤𝑤𝑤𝑤𝑜𝑜𝑤𝑤𝑑𝑑 𝐷𝐷𝑤𝑤𝐷𝐷𝑠𝑠 𝐷𝐷𝑤𝑤 𝐵𝐵𝐵𝐵𝐵𝐵 = 50 𝑖𝑖𝑚𝑚/ℎ 𝑚𝑚0.5 ℎ𝑡𝑡𝑚𝑚𝑤𝑤𝑜𝑜

1 = 25 𝑤𝑤𝑀𝑀 (5)

Because the round trip distance from original delivery route to reach BSS is 25 km, the one way trip to go BSS is 12.5 km. Based on this, to achieve its allowable time to go round trip from original delivery route to BSS, the company that wants to use the electric truck to deliver demand in the Netherlands needs to provide BSS each 12.5 km in the Netherlands. Following this logic, the possible numbers of BSS in the Netherlands can be predicted based on the following formula:

𝑃𝑃𝑤𝑤𝑜𝑜𝑜𝑜𝐷𝐷𝑃𝑃𝐷𝐷𝐷𝐷 𝑁𝑁𝑜𝑜𝑀𝑀𝑃𝑃𝐷𝐷𝑤𝑤𝑜𝑜 𝑤𝑤𝑓𝑓 𝐵𝐵𝐵𝐵𝐵𝐵 𝐷𝐷𝑤𝑤 𝑁𝑁𝐷𝐷𝐷𝐷ℎ𝐷𝐷𝑤𝑤𝐷𝐷𝐷𝐷𝑤𝑤𝑑𝑑𝑜𝑜

= 𝑁𝑁𝑒𝑒𝑡𝑡ℎ𝑒𝑒𝑤𝑤𝑡𝑡𝑡𝑡𝑤𝑤𝑑𝑑 𝑡𝑡𝑤𝑤𝑒𝑒𝑡𝑡 𝑜𝑜𝑠𝑠𝑡𝑡𝐷𝐷𝑒𝑒

�𝑎𝑎𝑎𝑎𝑎𝑎𝑎𝑎𝑎𝑎𝑎𝑎𝑎𝑎 𝑠𝑠𝑠𝑠𝑎𝑎𝑎𝑎𝑠𝑠 𝑥𝑥 𝑎𝑎𝑑𝑑𝑑𝑑𝑤𝑤𝑤𝑤𝑎𝑎𝑎𝑎𝑑𝑑𝑎𝑎 𝑡𝑡𝑚𝑚𝑘𝑘𝑎𝑎 𝑡𝑡𝑤𝑤 𝑡𝑡𝑤𝑤 𝑎𝑎𝑤𝑤 𝑎𝑎𝑤𝑤𝑚𝑚𝑤𝑤𝑠𝑠 𝑡𝑡𝑎𝑎𝑚𝑚𝑠𝑠 𝑡𝑡𝑤𝑤 𝐵𝐵𝐵𝐵𝐵𝐵 2𝑥𝑥�𝑎𝑎𝑎𝑎𝑎𝑎𝑎𝑎𝑎𝑎𝑎𝑎𝑎𝑎 𝑠𝑠𝑠𝑠𝑎𝑎𝑎𝑎𝑠𝑠 𝑥𝑥 𝑘𝑘𝑎𝑎𝑥𝑥𝑚𝑚𝑘𝑘𝑚𝑚𝑘𝑘 𝑠𝑠𝑎𝑎𝑚𝑚𝑑𝑑𝑑𝑑 𝑤𝑤𝑤𝑤𝑎𝑎𝑘𝑘𝑚𝑚𝑤𝑤𝑎𝑎 ℎ𝑤𝑤𝑚𝑚𝑎𝑎𝑠𝑠𝑅𝑅𝑗𝑗 � �

2

= 𝑁𝑁𝑒𝑒𝑡𝑡ℎ𝑒𝑒𝑤𝑤𝑡𝑡𝑡𝑡𝑤𝑤𝑑𝑑 𝑡𝑡𝑤𝑤𝑒𝑒𝑡𝑡 𝑜𝑜𝑠𝑠𝑡𝑡𝐷𝐷𝑒𝑒

�𝑎𝑎𝑎𝑎𝑎𝑎𝑎𝑎𝑎𝑎𝑎𝑎𝑎𝑎 𝑠𝑠𝑠𝑠𝑎𝑎𝑎𝑎𝑠𝑠 𝑥𝑥 𝑎𝑎𝑑𝑑𝑑𝑑𝑤𝑤𝑤𝑤𝑎𝑎𝑎𝑎𝑑𝑑𝑎𝑎 𝑡𝑡𝑚𝑚𝑘𝑘𝑎𝑎 𝑡𝑡𝑤𝑤 𝑡𝑡𝑤𝑤 𝑎𝑎𝑤𝑤 𝑎𝑎𝑤𝑤𝑚𝑚𝑤𝑤𝑠𝑠 𝑡𝑡𝑎𝑎𝑚𝑚𝑠𝑠 𝑡𝑡𝑤𝑤 𝐵𝐵𝐵𝐵𝐵𝐵 2 𝑥𝑥 𝐹𝐹𝑎𝑎𝑎𝑎𝐹𝐹𝑚𝑚𝑎𝑎𝑤𝑤𝐹𝐹𝑑𝑑 𝑡𝑡𝑤𝑤 𝑎𝑎𝑚𝑚𝑠𝑠𝑚𝑚𝑡𝑡 𝐵𝐵𝐵𝐵𝐵𝐵𝑗𝑗 �

2

= 𝑁𝑁𝑒𝑒𝑡𝑡ℎ𝑒𝑒𝑤𝑤𝑡𝑡𝑡𝑡𝑤𝑤𝑑𝑑 𝑡𝑡𝑤𝑤𝑒𝑒𝑡𝑡 𝑜𝑜𝑠𝑠𝑡𝑡𝐷𝐷𝑒𝑒

𝑜𝑜𝐹𝐹𝑚𝑚𝑡𝑡𝑤𝑤𝑒𝑒 𝑡𝑡𝑤𝑤𝑒𝑒𝑡𝑡 𝑜𝑜𝑠𝑠𝑡𝑡𝐷𝐷𝑒𝑒 𝑡𝑡𝑜𝑜 𝐵𝐵𝐵𝐵𝐵𝐵 𝑡𝑡𝑡𝑡𝐷𝐷𝑡𝑡𝑡𝑡𝑖𝑖𝑡𝑡𝑤𝑤 (6)

In this case, since the allowable time to go round trip from original delivery route to BSS is 0.5 hours. The possible numbers of BSS in the Netherlands are:

𝑃𝑃𝑤𝑤𝑜𝑜𝑜𝑜𝐷𝐷𝑃𝑃𝐷𝐷𝐷𝐷 𝑁𝑁𝑜𝑜𝑀𝑀𝑃𝑃𝐷𝐷𝑤𝑤𝑜𝑜 𝑤𝑤𝑓𝑓 𝐵𝐵𝐵𝐵𝐵𝐵 𝐷𝐷𝑤𝑤 𝑁𝑁𝐷𝐷𝐷𝐷ℎ𝐷𝐷𝑤𝑤𝐷𝐷𝐷𝐷𝑤𝑤𝑑𝑑𝑜𝑜 =12.5 𝑖𝑖𝑚𝑚 𝑚𝑚 12.5 𝑖𝑖𝑚𝑚^{41543 𝑖𝑖𝑚𝑚2} = 267 𝐵𝐵𝐵𝐵𝐵𝐵 (7)

15

Another possibility of distance between BSS and possible numbers of BSS based on the different allowable time to go round trip to BSS is shown in the table below. It is worth noting that this calculation number only hold for the needs of e-truck to visit BSS once. The distance between BSS decreases, and possible numbers of BSS increase if the frequency of going to BSS increases due to the limitation of battery distance range. For this case, the possible numbers of BSS in the Netherlands that will be used are 267 BSS since it is decided that the allowable time to go to round trip from original delivery route to BSs be 0.5 hours.

Table 1. Altenative Possible Numbers of BSS in The Netherlands allowable